Tropospheric Chemistry: Instruments

Acid CIMS (Chemical Ionization Mass Spectrometer) decommissioned

Principle of the Measurement

Negative ion proton transfer chemical ionization mass spectrometry using acetate ions as reagent ions

Species Measured

• All carboxylic acids (except acetic acid)
• All common inorganic acids
• Isocyanic acid (HNCO)
• Substituted Phenols

Time Response

10 second (nominal)

Detection Limit

5 - 50 pptv (background limited)

Accuracy

±(20% + det. limit)

Field Projects

• FireLab 2009
• CalNex 2010
• NACHTT 2011

Key Publications

Roberts, J.M., P.R. Veres, A.K. Cochran, C. Warneke, I.R. Burling, R.J. Yokelson, B. Lerner, J.B. Gilman, W.C. Kuster, R Fall, and J. de Gouw, Isocyanic acid in the atmosphere and its possible link to smoke-related health effects, Proc. Natl. Acad. Sci., doi:10.1073/pnas.1103352108, 2011.

Roberts, J.M., P. Veres, C. Warneke, J.A. Neuman, R. Washenfelder, S.S. Brown, M. Baasandorj, J. Burkholder, I.R. Burling, T.J. Johnson, R.J. Yokelson, and J. de Gouw, Measurement of HONO, HNCO, and other inorganic acids by negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS): Application to biomass burning emissions, Atmos. Meas. Tech., doi:10.5194/amt-3-981-2010, 2010.

Veres, P., J.M. Roberts, I.R. Burling, C. Warneke, J. de Gouw, R.J. Yokelson, Measurements of gas-phase inorganic and organic acids from biomass fires by negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), J. Geophys. Res., doi:10.1029/2010JD014033, 2010.

Veres, P., J.M. Roberts, C. Warneke, D. Welsh-Bon, M. Zahniser, S. Herndon, R. Fall, and J. de Gouw, Development of Negative-Ion Proton-Transfer Chemical-Ionization Mass Spectrometry (NI-PT-CIMS) for the Measurement of Gas-Phase Organic Acids in the Atmosphere, Int. J. Mass Spectrom., doi:10.1016/j.ijms.2008.04.032, 2008.